Method and apparatus for preventing warping of continuously cast metal



Dec. 13, 1955 Rossl EI'AL 2,726,430

METHOD AND APPARATUS FOR PREVENTING WARPING OF CONTINUOUSLY CAST METAL 2 Sheets-Sheet 1 Filed NOV. 18, 1952 FIG. I.

FIG.2.

INVENTORS. IRVING ROSS! DANIEL S. OGDEN ATTORNEYS.

Dec. 13, 1955 oss r 2,726,430

METHOD AND APPARATUS FOR PREVENTING WARPING 0F CONTINUOUSLY CAST METAL Filed NOV- 18, 1952 2 Sheets-Sheet 2 FIG. 3.

INVENTORS. IRVING ROSS! & DANIEL S. OGDEN United States Patent METHOD AND APPARATUS FOR. PREVENTING WARPING 0F CONTIN' UGUSLY" CAST METAL Irving Rossi, Morristown, and Daniel S. Ogden, Woodbridge, No L; as'siguors to Continuous Metalcast Co.,

Inc., Wilmington, Del., a corporation of Delaware Application November 13, 1952, Serial No. 321,167

' 3 Claims. 01-. 22 s7.2

This invention relates to the art of continuous casting of metals. I p

In continuous casting operations it has been observed that the casting which is withdrawn from the mold frequently exhibits a tendency to bend or warp. While this tendency has been observed in castings of various shapes, including round billets, it has been particularly pronounced in casting square or rectangular shapes.

In most continuous casting machines, the withdrawal of the casting is controlled by rollers which are located a convenient distance (usually several feet) below the mold, with the bight between the rollers aligned with the axis of the mold passage so as to receive the casting when it emerges in straight, unwarped condition. Then, at a still lower position a saw or other suitable cutting mechanism is also located in alignment with the mold passage for cutting the continuous casting into suitable lengths.

Warping of the casting, therefore, is inconvenient and troublesome at best, but in the larger sizes of castings such warping, if not corrected, becomes positively dangerous, and under some circumstances can damage or even wreck the entire casting machine.

It is an object of the present invention to provide means to automatically detect and correct such warping so that the casting will remain reasonably straight from the mold to the cut off position.

Other objects and advantages of the invention will appear hereinafter.

A preferred embodiment of the invention selected for purposes of illustration is shown in the accompanying drawings, in which:

Figure l is a top plan view of the apparatus, the casting being shown in section on the line 1-1 of Figure 2.

Figure 2 is a front elevation.

Figure 3 is a front elevation of a modified form of apparatus.

It has been discovered that the warping of a continuous casting is due primarily to uneven cooling of the peripheral surface of the casting which may be due to any one of several causes. When uneven cooling occurs, the side of the casting which has been cooled excessively becomes shorter than the opposite warmer side and the casting tends to assume a curved shape, concave on the short, cool side and convex on the long, hot side. In the distance between the mold and the rollers, this curvature may result in shifting the lower end of the casting several inches from its normal position.

According to the present invention we propose to correct this difficulty by providing means for detecting any departure from normal, uniform thermal conditions, and a valve or valves controlled by said means for applying additional cooling water to the hot side of the casting or less cooling water to the cool side of the casting, or both.

In the form of the invention illustrated in Figures 1 and 2 in which the casting 1 is shown emerging from mold 2, the detecting means is mechanical and comprises a roller 3 which is held in yielding engagement with the to a straight condition.

2,726,430 Patented Dec. 13 1955 2 surface of the casting by a spring. 4 which is: held under compression between the roller bracket. 5 and a guide 6; rod 7 connected to the bracket 5 passes through. guides 6' and 8 and is connected to a; lever 9 pivoted at 10-. The saidlever is connected, in turn, to a rod 11 which passes through guides 1 2 and 1'3. At appropriate oints, said rod carries pins I4 and 15 which engage slotsin levers l6 and: E7 which control valves 18 and I9 which control the water sprays directed. at: opposite sides or the casting. from nozzles and '2-1. Q

If, now, the conditions are such as to cause the casting to bend in the direction toward the roller 3', i. e. the side of the casting. which is engaged by the roller is the cooler side, the roller and rod 7 will be shiftedtothe left. This motion, transmitted through lever 9 to red H will cause the latter to: move to the right and tomove' the valve: levers 16 and 17 in clockwise direction. This movement of the valve levers mayaccomplish varying results depending on the setting of the valves.

The position of the valve levers shown in the drawings may be assumed to be a neutral position, and when in this position the valves may either be partially open to permit water to be sprayed against the casting, or the valves may be closed. If the valves are partially open, the clockwise motion of the valve levers 16 and 17 will then reduce the flow of water through nozzle 20 toward the cooler side of the casting and increase the flow of water through nozzle 21 toward the warmer side of the casting, thus tending to correct the warping and restoring the casting Alternatively, if the valves are closed when the valve levers are in neutral position, the clockwise motion of the valve levers will leave valve 18 closed, but will open valve 19 to direct cooling water toward the warmer side of the casting.

If the casting warps in the opposite direction, i. e. away from the roller 3, the roller will follow, of course, and through rod 7, lever 9 and rod 11 will produce counterclockwise motion of the valve levers to reduce or stop the flow through nozzle 21 and to increase or start flow through nozzle 20.

In the form of the invention previously described, it is advantageous to have the sprays located in advance of (i. e. above) the detecting means. In an alternative form of the invention, however, in which a thermo-electric detecting means is used, the detecting means is located in advance of the sprays. Thus, referring to Figure 3, thermo-electric detecting elements 31 and 32 are placed on opposite sides of the casting in position to sense the temperatures of the adjacent surfaces of the casting.

Any suitable form of thermo-elective detecting elements may be used which generate an electromotive force which varies with temperature changes such as thermocouples, for example, but we prefer to use rayotubes because of their sensitivity and accuracy. The variable electric current generated in the detecting elements is fed through conductors 33 and 34 to electronic units 35 and 36 which amplify the current and utilize the amplified current to actuate or control the actuation of solenoids which control valves 37 and 38.

If the detecting element 31 indicates that the opposed face of the casting is becoming hotter or cooler, it serves to open or close the valve 37 to increase or decrease the cooling on that side. Likewise, if the detecting element 32 indicates variations in temperature of the opposite face of the casting, valve 38 will be opened or closed to make an appropriate connection.

It will be understood that although only two detecting 1. In apparatus for the continuous casting of metal in which the casting is withdrawn continuously from the lower end of a casting mold, nozzles located adjacent opposite faces of said casting to direct cooling fluid against said faces as said casting moves longitudinally past said nozzles, valves for controlling the flow through said nozzles, means also located adjacent said opposite faces of said casting between the casting mold and said nozzles to detect departures from normal, uniform thermal conditions as said casting moves longitudinally past said means, and means controlled by said detecting means to operate said valves to increase the flow of cooling fluid through said nozzles against a hotter face of the casting and to decrease the flow of cooling fluid through said nozzles against a cooler face of the casting.

2. Apparatus as claimed in claim 1 which said detecting means are therrno-electric elements which generate an electromotive force which varies with changes in term perature.

3. The method of correcting the bending or warping of a continuous casting as said casting is withdrawn coni 4 tinuously from a casting mold, which comprises, directing cooling. fluid against opposite faces of the casting at a region below the casting mold, detecting departures from normal, uniform thermal conditions in the casting, and controlling the relative rate of flow of cooling fluid against the respective opposite faces of the casting in accordance with observed departures from normal to increase the relative rate of flow against a hotter face of the casting in order to restore normal, uniform, thermal conditions.

References Cited in the file of this patent UNITED STATES PATENTS 2,215,576 Bucknam et a1. Sept. 24, 1940 2,225,373 Goss Dec.'17, 1940 2,246,907 Webster June 24, 1941 2,284,503 Williams May 26, 1942 2,338,781 Porter Jan. 11, 1944 2,428,825 Arnoldy Oct. 14, 1947 2,623,531 Waddington et al. Dec. 30, 1952 

1. IN APPARATUS FOR THE CONTINUOUS CASTING OF METAL IN WHICH THE CASTING IS WITHDRAWN CONTINUOUSLY FROM THE LOWER END OF A CASTING MOLD, NOZZLES LOCATED ADJACENT OPPOSITE FACES OF SAID CASTING TO DIRECT COOLING FLUID AGAINST SAID FACES AS SAID CASTING MOVES LONGITUDINALLY PAST SAID NOZZLES, VALVES FOR CONTROLLING THE FLOW THROUGH SAID NOZZLES, MEANS ALSO LOCATED ADJACENT SAID OPPOSITE FACES OF SAID CASTING BETWEEN THE CASTING MOLD AND SAID NOZZLES TO DETECT DEPARTURES FROM NORMAL, UNIFORM THERMAL CONDITIONS AS SAID CASTING MOVES LONGITUDINALLY PAST SAID MEANS, AND MEANS CONTROLLED BY SAID DETECTING MEANS TO OPERATE SAID VALVES TO INCREASE THE FLOW OF COOLING FLUID THROUGH SAID NOZZLES AGAINST A HOTTER FACE OF THE CASTING AND TO DECREASE THE FLOW OF COOLING FLUID THROUGH SAID NOZZLES AGAINST A COOLER FACE OF THE CASTING. 